Re: [PATCH] perf pmu: Fix perf stat output with correct scale and unit

[Ian Rogers]

On Tue, Sep 26, 2023 at 3:51 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
>
> On Wed, Sep 20, 2023 at 9:02 AM Ian Rogers <irogers@xxxxxxxxxx> wrote:
> >
> > On Wed, Sep 20, 2023 at 5:24 AM Wyes Karny <wyes.karny@xxxxxxx> wrote:
> > >
> > > The perf_pmu__parse_* functions for the sysfs files of pmu event’s
> > > scale, unit, per-pkg and snapshot were updated in commit 7b723dbb96e8
> > > ("perf pmu: Be lazy about loading event info files from sysfs").
> > > However, the paths for these sysfs files were incorrect. This resulted
> > > in perf stat reporting values with wrong scaling and missing units. This
> > > is fixed by correcting the paths for these sysfs files.
> > >
> > > Before this fix:
> > >
> > >  $sudo perf stat -e power/energy-pkg/ -- sleep 2
> > >
> > >  Performance counter stats for 'system wide':
> > >
> > >    351,217,188,864      power/energy-pkg/
> > >
> > >           2.004127961 seconds time elapsed
> > >
> > > After this fix:
> > >
> > >  $sudo perf stat -e power/energy-pkg/ -- sleep 2
> > >
> > >  Performance counter stats for 'system wide':
> > >
> > >              80.58 Joules power/energy-pkg/
> > >
> > >              2.004009749 seconds time elapsed
> > >
> > > Fixes: 7b723dbb96e8 ("perf pmu: Be lazy about loading event info files from sysfs")
> > > Signed-off-by: Wyes Karny <wyes.karny@xxxxxxx>
> >
> > Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>
>
> Applied to perf-tools-next, thanks!

Thanks Namhyung, I think this should be a candidate for perf-tools so
that 6.6 doesn't regress for sysfs events.

Ian